I. Field of the Present Invention
The present invention relates generally to receptacles for the storage of hydrocarbon vapors, and more particularly to such a receptacle in the form of an insulation blanket adapted to be mounted to a motor vehicle panel.
II. Description of the Prior Art
It is well known that fuel used in internal combustion engines such as gasoline is very volatile and easily vaporizes. Of course, such vaporization is important since the vaporized fuel is injected or otherwise aspirated into the engine cylinders where combustion occurs. Nevertheless, vaporization which occurs naturally under normal atmospheric conditions and temperatures has been considered undesirable not only due to the potential for explosion during the handling of the fuels, but also because the hydrocarbon vapors are considered to be harmful pollutants. Thus, it has been desirable to restrict the release of the hydrocarbon vapors to the atmosphere. Moreover, in the interest of conserving fuel energy, vapor recovery systems have been utilized in motor vehicles.
One previously known vapor recovery system is shown in U.S. Pat. No. 3,884,204 to Krautwurst et al. In that system, a first vapor recovery circuit includes an air purged canister filled with vapor adsorbtive material which is connected to a ported vacuum connection in the carburetor. The patent discloses a rigid canister whose interior is filled with an active vapor adsorbing material such as activated charcoal. In addition, the patent teaches a second vapor recovery circuit including a second canister connected in fluid communication with the filler neck of the fuel tank. The patent teaches that the use of two separate canisters is advantageous over the use of a single large capacity canister, since the canisters can be purged at different rates to avoid adverse engine operation or increased exhaust emissions of unburned hydrocarbons. Nevertheless, such a system requires that space be provided for the two separate canisters and thus increases the difficulty of packaging the system within a motor vehicle.
Moreover, in view of the fact that there has been increases interest in controlling the emission of fuel vapors during refueling of the motor vehicle, the previously known canisters adapted to store vapors emitted in the fuel tank of the vehicle are insufficient to control the large amount of vapors which are released during refueling of the vehicle. Thus, U.S. Pat. No. 4,058,147 to Stary et al., discloses a vapor recovery system adapted to be employed at the pumping station where refueling occurs. However, such a system is not adapted to be incorporated in a motor vehicle itself, and it is therefore effective only when a particular pumping station, which is specially constructed with the recovery system, is used to supply fuel to a motor vehicle. Thus, previously known vapor recovery systems do not teach or suggest a means for compactly fitting a large capacity vapor adsorption canister in existing motor vehicle configurations.